Clamp for shifting annular workpieces in a forging press



Aug 19, 1958 K. LlcHTr-:NFELD 2,847,886

CLAMP FOR SHIFTING ANNULAR WORKPIECES IN A FORGING PRESS Filed Sept. l5, 1954 INVENTOR //JQL MWrE/VFELD United States CLAMP FOR SHIFTING ANNULAR WORKPIECES IN A FORGING PRESS 4 Claims. (Cl. 78-98) This invention relates to forging presses, and more arent O particularly to a device for the incremental shifting of large rings or the like on the mandrel and relative to the die means of a forging press.

During the forging of rings, band irons, flanges, bottoms of tubes, or the like annular objects on a mandrel in a forging press, the ring or the like must be turned through a certain angle of its circumference after each stroke of the press. Hitherto, said intermittent turning of the ring or the like is carried out by hand, and the operator of the forging press is obliged to defer the subsequent stroke of the press until the ring or the like has been brought manually into its new position. The lelliciency of this procedure depends to a great deal on the aptitude of the operators as the turning of the ring or the like should take place in steps as uniform as possible. A uniform step by step advancing or turning of the ring or the like is highly desirable for a uniform forging and a high degree of observance of the required dimensions of the work to be forged. This accurateness can hardly be obtained by a manual turning of the ringor the like, and, furthermore, the manual turning of the ring or the like requires extremely hard work by the forgets, especially if the rings are of large size.

An object of the invention is to provide a device by means of which the turning of rings or the like on the mandrel in a forging press may be automatically performed.

Another object of the invention is to provide a device for turning rings or the like through a predetermined angle on the mandrel in a forging press during intervals between strokes of the forging press.

Other objects and structural details of the invention will be apparent from the following description when read in conjunction with the drawings, wherein the figure illustrates a fragmentary perspective view of a forging press employing a workpiece-turning device according to the invention.

Referring now to the drawing, 10 generally indicates a support of the forging press. The cross-head 4 of the forging press is reciprocably mounted on said support 10 for the performance of downward and upward movements.

A work in the shape of a ring 1 to be forged rests on a mandrel 2 carried by a U-shaped supporting member 3, which, in turn, is placed on the anvils 11. The upper portion of the dening wall of the passage of the ring 1 is in engagement with the mandrel 2 by which the ring 1 is suspendedly and rotatably supported.

Two hooks 5 are engaged with the cross-head 4. A chain 6 is suspended from each hook 5. Clamping means or clamping tongs, generally indicated by 12 are carried by the chains 6. Said clamping means 12 comprises a pair of forked side elements 7 and a. straight cross-bar 8 pivotally engaged with said side elements 7 at 13 and 14 respectively. The cross-bar 8 has a series of holes 15 for selective insertion of the pins 13 and 14. The ends of the cross-bar 8 are inserted into the spaces between the legs of the forked side elements 7. VThe side elements 7 are provided with a series of notches 16 for selective engagement with the pins 13 and 14 respectively of the cross-bar 8. Furthermore, each side ele# ment 7 has a hook 17 for engagement with a link of the associated chain 6.

The effective length of the chains 6 between their points of engagement with the hooks 5 and 17 is chosen in such a manner, that upon engagement of the clamping means 12 with the ring 1 or the like to be forged the chains 6 are at an angle of approximately 20 to 30 to the vertical line. Furthermore, the pins 13 and 14 are inserted into such holes 15 of the cross-bar 8, that the front ends of the side elements 7 of the clamping means 12 are at such a distance from each other, that upon an upward movement of the cross-head 4 of the forging press and, thus, upon a pulling on the chains 6 the ring 1 is clamped at the opposite side faces thereof between the side elements 7 while its outer peripheral surface is frictionally engaged by the cross-bar 8, whereby the ring will be dragged along over the mandrel. Upon a subsequent lowering of the cross-head 4 during a pressing stroke of the forging press the chains are loosened so that the clamping means 12 is likewise loosened and the cross-bar S thereof moves along the circumference of the ring 1 through a predetermined distance.

The forgets assigned to work on a forging press equipped with the clamping means 12 merely 'have to watch for a uniform run of the operations; they are relieved from any hard bodily work. Moreover, the use of the device according to the invention has substantial technical advantages. The pressing strokes of the forging press may succeed each other within very short intervals, as the advancing or turning of the ring or the like to be forged takes place automatically during the upward movement of the cross-head of the forging press. Furthermore, the operator of the forging press may readily control the ldegree of advancing or turning of the ring by a corresponding control of the degree of the upward movement of the cross-head.

Gwing to above mentioned features the entire forging operation takes place within a period which is considerably shorter than the time needed by the use of hitherto customary forging presses without the automatic turning device according to the invention. When the device according to the invention is used, a far reaching working of the ring or the like may be obtained in a single heat Thus, additional time is saved, as a repetition of the heating of the ring or the like becomes less frequent.

Furthermore, the quality of the forged articles is considerably improved owing to the uniformity of the step by step turning of the article during the forging operation, so that a subsequent dressing of the articles may be eliminated.

I have described a preferred embodiment of my invention, but it is understood that this disclosure is for the purpose of illustration and that various omissions or changes in shape, proportion and arrangements of parts, as well as the substitution of equivalent elements for those, herein shown and described may be made without departing from the spirit and scope of the invention as set forth in the appended claims.

What I claim is:

1. A clamp for use in shifting a substantially annular object having an outer peripheral surface and opposite side faces over a horizontal member arranged to extend through said object and support the latter, comprising a pair of elongated clamping elements arranged to be located on opposite sides and substantially chordally of said object when the same is supported by said member, said elements being engageable with said side faces of said object, respectively, a cross-bar pivotally connected to both said clamping elements and arranged to extend across said outer peripheral surface of said object and from one of said side faces thereof to the other when said clamping elements are located chordally of said bject, and means connected to said clamping elements, re-

spectively, for drawing said cross-bar against and intov frictional gripping Contact with said outer peripheral surface of said object and simultaneously pivoting said clamping elements toward one another into clamping engagement with said side faces of said object in response to a force directed longitudinally of said clamping elements and away from said cross-bar, thereby enabling shifting of said object through a predetermined angle over said member, and for loosening said clamping elements and said cross-bar from said object in response to relaxi ation of said force so as to permit said clamping elements and said cross-bar to slide freely over said object without shifting the same on said member.

2. A clamp according to claim 1, a pair of pins projecting from said cross-bar at spaced locations thereon and substantially at right angles to the plane of pivotal movement of said clamping elements, each of said clamping elements being provided with at least one set of lon` gitudinally spaced. recesses adapted, respectively, to receive said pins, said pins and corresponding ones of said recesses constituting adjustable pivotal connections between said clamping elements and said cross-bar, whereby objects of different diameters may be operated upon by the clamp.

3. A clamp according to claim 2, said crossbar being provided with a plurality of apertures spaced from each other lengthwise ,of said cross-bar and dimensioned to receive said pins, respectively, whereby, the distance between the axes of pivotal movement of said clamping elements #l may be varied to enable objects having outer peripheral surfaces` of different widths to be operated upon by the clamp.

4. For use with a forging press or the like, a clamp to shift a substantially annular object having an outer peripheral surface and opposite side faces, and mounted on its inner periphery over a horizontal member which is arranged to extend therethrough, comprising, a pair of,

elongated clamping elements arranged on opposite sides of and substantially chordally of said object, a cross-bar pivotally connected to each of said clamping elements andrarrangedto extend across the outer peripheral surface of said object from one of said side faces to the other, and means connected to said clamping element for drawing said crossbar against and into frictional gripping Contact with the outer peripheral surface of said object and simultaneously pivoting said clamping elements toward one another into clamping engagement with said side faces of said object in response to a force directed longitudinally of said clamping velements and away from said crossbar, thereby enabling shifting of said object to a predetermined angle over said member, and for loosening said clamping elements and said crossbar from said object in response to relaxation of said force so as to permit said clamping elements and said crossbar to slide freely over said object without shifting the same on said member.

References Cited in the file of this patent UNITED STATES PATENTS 14,282 Cass Feb. 19, 1365 532,488 Simpson Jan. 15, 1895 542,985 Bolsinger July 23, 1895 823,667 Childress June 19, 1906 

